20" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Red Oak Wood + Product Details Size -

+ Product Details Size - 26"w X 10"h is the size for the duct opening measurement only

+ Product Details Size – 18" x 34" or 34" x 18" is the size for the duct opening measurement only

actual front end outer dimensions are approximately 28 5/8" width X 26 5/8" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 12" x 6" or 6" x 12" duct opening (measured at the opening)

20" x 22" Cube Core Eggcrate Return Air Filter Grille for 1" Filter Color_Red Oak Wood + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 20" x 22" OR 22" x 20" duct opening (measured at the opening), with actual outer dimensions of 22. 5" W x 24. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 19. 75" x 21. 75" x 1" Premium Airflow Efficiency High performance cube core eggcrate design allows 95% airflow efficiency, reducing energy costs and maximizing HVAC system lifespan. Durable, Rust Free Aluminum